From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Thu, 6 Aug 2009 17:39:54 +0000 (-0300)
Subject: KVM: set debug registers after "schedulable" section
X-Git-Tag: v2.6.27.32~31
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=12daed95faec51a60736776a35ce4b0d1541c346;p=thirdparty%2Fkernel%2Fstable.git

KVM: set debug registers after "schedulable" section

(cherry picked from commit 29415c37f043d1d54dcf356601d738ff6633b72b)

The vcpu thread can be preempted after the guest_debug_pre() callback,
resulting in invalid debug registers on the new vcpu.

Move it inside the non-preemptable section.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5911677d1d7b3..1454992e6ace1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2839,10 +2839,6 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	down_read(&vcpu->kvm->slots_lock);
 	vapic_enter(vcpu);
 
-preempted:
-	if (vcpu->guest_debug.enabled)
-		kvm_x86_ops->guest_debug_pre(vcpu);
-
 again:
 	if (vcpu->requests)
 		if (test_and_clear_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests))
@@ -2896,6 +2892,9 @@ again:
 		goto out;
 	}
 
+	if (vcpu->guest_debug.enabled)
+		kvm_x86_ops->guest_debug_pre(vcpu);
+
 	vcpu->guest_mode = 1;
 	/*
 	 * Make sure that guest_mode assignment won't happen after
@@ -2970,7 +2969,7 @@ out:
 	if (r > 0) {
 		kvm_resched(vcpu);
 		down_read(&vcpu->kvm->slots_lock);
-		goto preempted;
+		goto again;
 	}
 
 	post_kvm_run_save(vcpu, kvm_run);